This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of the study is to develop future studies that will help researchers to learn more about the prevention of type 1 diabetes and how diabetes occurs. Relatives of people with type 1 diabetes have a 10 to 15 times greater risk for the disease than people with no family history. Because of this, we are interested in looking at close blood relatives of people with type 1 diabetes. The study is divided into three phases: Screening Phase 1, Baseline Risk Assessment Phase 2, and Follow-Up Risk Assessments Phase 3. Phase I - The screening phase of the study includes testing for diabetes related autoantibodies in the blood. Autoantibodies are proteins that are made by the body?s immune system. If these proteins are present, it could mean that cells in the pancreas that produce insulin are damaged. Autoantibodies can be found in the blood years before type 1 diabetes occurs. Several different kinds of autoantibodies can be seen. Phase II - More testing done to find out or estimate the risk for type 1 diabetes. Phase III - Is for those subjects whose test results showed that they are at a higher risk of developing type 1 diabetes than others. It involves several ongoing risk assessment tests to see if these subjects might be eligible to participate in any diabetes prevention trials